Poa annua

Tufted annual or short-lived perennial; culms 5-30cm high, erect, spreading or prostrate, sometimes with a creeping base rooting from the nodes, slightly compressed. Leaf-blades flat or folded, 1-14cm long, 1–2(–5)mm wide, flaccid, abruptly tapered to a pointed or bluntly hooded tip, often transversely wrinkled, scaberulous on the margins; ligule blunt, 2–5mm long. Panicle ovate or pyramidal, (1–)3–8(–12)cm long, loose or rather dense; branches paired, spreading or de-flexed after anthesis, smooth. Spikelets with 3–5(-10) closely spaced florets, ovate or oblong, 3–10mm long, pale or bright green, reddish or purplish; glume unequal, the lower lanceolate to ovate, 1.5–3mm long, 1–nerved, the upper elliptic or oblong, 2–4mm long, 3–nerved; lemmas semi-elliptic or oblong in side-view, 2.5–4mm long, blunt, glabrous or sparsely to densely ciliate on the keel and nerves, without any wool at the base; palea nearly as long as the lemma, ciliate all along the keels; anthers 0.6–0.8(–1)mm long.

Annuals, Terrestrial, not aquatic, Stems nodes swollen or brittle, Stems geniculate, decumbent, or lax, sometimes rooting at nodes, Stems mat or turf forming, Stems caespitose, tufted, or clustered, Stems terete, round in cross section, or polygonal, Stems compressed, flattened, or sulcate, Stems branching above base or distally at nodes, Stem internodes hollow, Stems with inflorescence less than 1 m tall, Stems, culms, or scapes exceeding basal leaves, Leaves mostly basal, below middle of stem, Leaves c onspicuously 2-ranked, distichous, Leaves sheathing at base, Leaf sheath mostly open, or loose, Leaf sheath smooth, glabrous, Leaf sheath or blade keeled, Leaf sheath and blade differentiated, Leaf blades linear, Leaf blades very narrow or filiform, less than 2 mm wide, Leaf blades 2-10 mm wide, Leaf blades mostly flat, Leaf blade margins folded, involute, or conduplicate, Leaf blades mostly glabrous, Leaf blades more or less hairy, Ligule present, Ligule an unfringed eciliate membrane, Inflorescence terminal, Inflorescence an open panicle, openly paniculate, branches spreading, Inflorescence solitary, with 1 spike, fascicle, glomerule, head, or cluster per stem or culm, Inflorescence with 2-10 branches, Inflorescence branches more than 10 to numerous, Flowers bisexual, Spikelets pedicellate, Spikelets laterally compressed, Spikelet less than 3 mm wide, Spikelets with 3-7 florets, Spikelets solitary at rachis nodes, Spikelets all alike and fertille, Spikelets bisexual, Spike lets disarticulating above the glumes, glumes persistent, Spikelets disarticulating beneath or between the florets, Rachilla or pedicel glabrous, Glumes present, empty bracts, Glumes 2 clearly present, Glumes equal or subequal, Glumes distinctly unequal, Glumes shorter than adjacent lemma, Glumes keeled or winged, Glumes 3 nerved, Lemmas thin, chartaceous, hyaline, cartilaginous, or membranous, Lemma similar in texture to glumes, Lemma 5-7 nerved, Lemma glabrous, Lemma body or surface hairy, Lemma apex acute or acuminate, Lemma awnless, Lemma margins thin, lying flat, Lemma straight, Palea present, well developed, Palea about equal to lemma, Palea 2 nerved or 2 keeled, Stamens 3, Styles 2-fid, deeply 2-branched, Stigmas 2, Fruit - caryopsis, Caryopsis ellipsoid, longitudinally grooved, hilum long-linear.

Annuals, sometimes over wintering, infrequently stoloniferous. Culms loosely tufted, erect or oblique, often decumbent, often geniculate, soft, 6–30(–45) cm tall, smooth, nodes 1 or 2(or 3), 1(or 2) exserted. Leaf sheath slightly compressed, thin, smooth, uppermost closed for ca. 1/3 of length; blade light to dark green, flat or folded, thin, 2–12 cm × (0.8–)1–3.5 mm, margins slightly scabrid, apex acutely prow-tipped; ligules 0.6–3 mm, abaxially smooth, glabrous, apex obtuse, margin irregularly dentate, smooth. Panicle open, moderately congested, broadly ovoid to pyramidal, (1–)3–10 cm, as long as wide; branches ascending, spreading, or a few reflexed, 1 or 2(–3) per node, smooth, longest with usually 3–5 spikelets in distal 1/2. Spikelets ovate to oblong, dark to light green, (3–)4–5.5 mm, florets 3–5, distal fertile florets often female; vivipary absent; rachilla internodes 0.5–1.5 mm, smooth, glabrous, hidden or exposed; glumes unequal, smooth or rarely keeled with hooks, lower glume lanceolate and acute to subflabellate and obtuse, 1.5–2(–3) mm, 1-veined, upper glume elliptic, 2–3(–4) mm, 3-veined, the margin angled; lemmas ovate, 2.2–3.5 mm, apex and margins broadly membranous, intermediate veins prominent, keel and marginal, and usually intermediate, veins villous in the lower 1/2, rarely glabrous throughout; callus glabrous; palea keels smooth, densely pilulose to short villous. Anthers 0.6–1 mm, usually at least 2 × as long as wide, or vestigial. Fl. Apr–May, fr. Apr–Jul. 2n = 28.

2300-3500 m

This non-native grass is a spring or fall annual that completes its life cycle within a short period of time (about 6 weeks). It is usually quite small, consisting of a low tuft of vegetation about 4" across and 1½" tall. However, substantially larger plants are sometimes observed. The typical plant has sprawling culms about 2½" long that are unbranched, except at the base. They are light green, glabrous, terete, and largely covered by the sheaths. The blades of the alternate leaves are 1½" long and 1/8" (2.5 mm.) across; they are dull to bright green, hairless, and keel-shaped at their tips. The leaf sheaths are light to medium green, hairless, open, and longitudinally veined. At the junction of each sheath and blade, the ligule consists of a papery membrane. Each culm terminates in a flattened panicle of spikelets about ¾" long and ½" across. In atypical plants, the culms, leaf blades, and panicles are larger in size than what is indicated above. The somewhat flattened spikelets are light or whitish green. Each spikelet is about 4.5 mm. long and 2 mm. across; it consists of 2 glumes and 3-6 lemmas that are arranged in two columnar ranks. The curved glumes are oblong-lanceolate in shape and membranous along their margins; the larger glume is about 2.0 mm. long, while the smaller glume is about 1.5 mm. long. The curved lemmas are elliptic-ovate in shape, membranous along their margins, and faintly veined; sometimes there is a reddish purple patch near the apex of each lemma. The lemmas are often pubescent along their veins. Unlike many other Poa spp. (Bluegrasses), there is no web of hairs at the base of each lemma. The blooming period occurs during the spring or fall. During the hot weather of summer (or sub-freezing weather of winter), this grass dies down and becomes tan, dispersing its seeds. The root system is shallow and fibrous. This grass reproduces primarily by reseeding itself; less often, it may form rootlets at the nodes of the leaves. Small colonies of plants are formed occasionally.

This dwarf grass is easy to overlook, particularly when it grows in close proximity to other grasses. For a Poa sp. (Bluegrass), it has short leaf blades and rather plump-looking seedheads. It is fairly easy to identify because of its small size and low sprawling stems. To determine the technical characteristics of this and other Bluegrasses, it is highly desirable to use a good 10x hand lens. Such lenses can be used to detect the presence (or absence) of a web of hairs at the base of a lemma. Some Bluegrasses superficially resemble Eragrostis spp. (Love Grasses), but the latter have tufts of hair at the junction of the blades and sheaths. Bluegrasses lack such tufts of hair.

Erect or decumbent annual (very rarely perennial), 5–30 cm. Leaves: ligule 2–3 mm; lamina 1.5–10 × 0.1–0.5 cm, flat, keeled, often transversely wrinkled. Panicle 1–8 cm, ± triangular; branches usually 2 together, often becoming reflexed after flowering. Spikelets 3–5 mm, 3–5-flowered, lanceolate; lower glume ovate or lanceolate, 1-veined; upper 3-veined; lemma ovate, 5-veined, margin and apex broadly hyaline.

annua: annual

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Global Distribution

Cosmopolitan

Indian distribution

State - Kerala, District/s: Idukki

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Annual Bluegrass is common in most areas of Illinois, although it hasn't been collected from all counties. It is native to Eurasia. Habitats include fields and pastures, lawns and gardens, waste ground, and damp paths in meadows, woodlands, and grassy urban areas. Disturbed areas are strongly preferred. This grass is more abundant during the spring than the fall.

Nile region, Oases, Mediterranean region and Sinai.

Cosmopolitan.

Poa annua fo. purpurea Mike L.Grant:
United Kingdom (Europe)

Note: This information is based on publications available through Tropicos and may not represent the entire distribution. Tropicos does not categorize distributions as native or non-native.

Poa annua fo. lanuginosa Sennen:
Spain (Europe)

Note: This information is based on publications available through Tropicos and may not represent the entire distribution. Tropicos does not categorize distributions as native or non-native.

Poa hohenackeri Trin.:
Russian Federation (Asia)

Note: This information is based on publications available through Tropicos and may not represent the entire distribution. Tropicos does not categorize distributions as native or non-native.

Poa annua fo. reptans (Hausskn.) T. Koyama:
Japan (Asia)

Note: This information is based on publications available through Tropicos and may not represent the entire distribution. Tropicos does not categorize distributions as native or non-native.

Poa annua var. aquatica Asch.:
United States (North America)

Note: This information is based on publications available through Tropicos and may not represent the entire distribution. Tropicos does not categorize distributions as native or non-native.

Poa annua fo. annua :
Japan (Asia)

Note: This information is based on publications available through Tropicos and may not represent the entire distribution. Tropicos does not categorize distributions as native or non-native.

Poa royleana Nees ex Steud.:
India (Asia)

Note: This information is based on publications available through Tropicos and may not represent the entire distribution. Tropicos does not categorize distributions as native or non-native.

Poa annua var. annua :
Canada (North America)
United States (North America)
China (Asia)

Note: This information is based on publications available through Tropicos and may not represent the entire distribution. Tropicos does not categorize distributions as native or non-native.

Poa aestivalis J. Presl:
Peru (South America)

Note: This information is based on publications available through Tropicos and may not represent the entire distribution. Tropicos does not categorize distributions as native or non-native.

Poa meyenii Nees & Meyen:
Peru (South America)

Note: This information is based on publications available through Tropicos and may not represent the entire distribution. Tropicos does not categorize distributions as native or non-native.

Poa annua var. reptans Hausskn.:
Canada (North America)
United States (North America)
China (Asia)

Note: This information is based on publications available through Tropicos and may not represent the entire distribution. Tropicos does not categorize distributions as native or non-native.

Poa annua L.:
Austria (Europe)
Afghanistan (Asia)
Algeria (Africa & Madagascar)
Albania (Europe)
Argentina (South America)
Australia (Oceania)
Azores (Africa & Madagascar)
Baleares (Europe)
Belarus (Europe)
Belgium (Europe)
Burma (Asia)
Bolivia (South America)
Brazil (South America)
Bhutan (Asia)
Canada (North America)
Chile (South America)
Czechoslovakia (Europe)
Cameroon (Africa & Madagascar)
China (Asia)
Colombia (South America)
Costa Rica (Mesoamerica)
Cyprus (Asia)
Denmark (Europe)
Germany (Europe)
Andorra (Europe)
Ecuador (South America)
France (Europe)
Guyana (South America)
Honduras (Mesoamerica)
Peru (South America)
Panama (Mesoamerica)
Greenland (North America)
Mexico (Mesoamerica)
Guatemala (Mesoamerica)
El Salvador (Mesoamerica)
Nicaragua (Mesoamerica)
Kenya (Africa & Madagascar)
Ethiopia (Africa & Madagascar)
India (Asia)
Iraq (Asia)
Iran (Asia)
Pakistan (Asia)
Greece (Europe)
Lesotho (Africa & Madagascar)
Namibia (Africa & Madagascar)
Swaziland (Africa & Madagascar)
Paraguay (South America)
Malaysia (Asia)
Saudi Arabia (Asia)
Qatar (Asia)
South Korea (Asia)
North Korea (Asia)
Morocco (Africa & Madagascar)
Lebanon (Asia)
Israel (Asia)
Egypt (Africa & Madagascar)
Syria (Asia)
Russian Federation (Asia)
Sweden (Europe)
Corsica (Europe)
Sardegna (Europe)
Poland (Europe)
Romania (Europe)
Sicilia (Europe)
Spain (Europe)
Switzerland (Europe)
Portugal (Europe)
Estonia (Europe)
Gibraltar (Europe)
Faeroe Isl. (Europe)
Finland (Europe)
Hungary (Europe)
Ireland (Europe)
Iceland (Europe)
Italy (Europe)
Liechtenstin (Europe)
Latvia (Europe)
Kriti (Europe)
Lithuania (Europe)
Moldova (Europe)
Netherlands (Europe)
Norway (Europe)
Northern Ireland (Europe)
Equatorial Guinea (Africa & Madagascar)
Madagascar (Africa & Madagascar)
Japan (Asia)
New Zealand (Oceania)
Nepal (Asia)
Irian Jaya (Asia)
New Guinea (Asia)
Sumatra (Asia)
Tajikistan (Asia)
Kazakhstan (Asia)
Kyrgyzstan (Asia)
Mongolia (Asia)
Sri Lanka (Asia)
United States (North America)
Caribbean (Caribbean)
Tanzania (Africa & Madagascar)
Uganda (Africa & Madagascar)
Uruguay (South America)
Venezuela (South America)
United Arab Emirates (Asia)
Yemen (Asia)
Turkey (Asia)
Turkmenistan (Asia)
United Kingdom (Europe)
Bulgaria (Europe)
Yugoslavia (Europe)
Svalbard (Europe)
Zimbabwe (Africa & Madagascar)
Zambia (Africa & Madagascar)
Vietnam (Asia)
Hawaiian Isl (Oceania)
Lesser Sunda Isl (Asia)
Taiwan (Asia)
Ukraine (Europe)
Uzbekistan (Asia)
South Africa (Africa & Madagascar)
Borneo (Asia)
Papua New Guinea (Asia)
Philippines (Asia)

Note: This information is based on publications available through Tropicos and may not represent the entire distribution. Tropicos does not categorize distributions as native or non-native.

Anhui, Fujian, Gansu, Guangdong, Guangxi, Guizhou, Hainan, Hebei, Heilongjiang, Henan, Hubei, Hunan, Jiangsu, Jiangxi, Jilin, Liaoning, Nei Mongol, Qinghai, Shaanxi, Shandong, Shanxi, Sichuan, Taiwan, Xinjiang, Xizang, Yunnan, Zhejiang [Afghanistan, Bhutan, India, Indonesia, Japan, Kazakhstan, Korea, Kyrgyzstan, Malaysia, Mongolia, Myanmar, Nepal, New Guinea, Pakistan, Russia, Sri Lanka, Tajikistan, Turkmenistan, Uzbekistan, Vietnam; Africa, SW Asia, Australia, Europe, North and South America, Pacific Islands].

Canada

Origin: Exotic

Regularity: Regularly occurring

Currently: Unknown/Undetermined

Confidence: Confident

United States

Origin: Exotic

Regularity: Regularly occurring

Currently: Unknown/Undetermined

Confidence: Confident

Distribution: Pakistan (Baluchistan, Punjab, N.W.F.P. & Kashmir); cosmopolitan, but avoiding deserts and hot climates.

Cosmopolitan.

"Annuals; culms 15-20 cm high, tufted; nodes glabrous. Leaves 5-10 x 0.2-0.3 cm; rounded at base, glabrous; sheath keeled, glabrous; ligule membranous. Panicle 5-6 x 2 cm, contracted; branches filiform, glabrous. Spikelets similar, 5-6 mm long, ovate, glabrous; lower glume 2 x 0.5 mm, lanceolate, 1-nerved; upper glume 2.5 x 1 mm, ovate, acute, 3-nerved; florets 2-4, similar; upper florets exerted; lemmas 3 x 1 mm, ovate-lanceolate, 3-5-nerved, hairy along the nerves; palea 3 x 0.75 mm, lanceolate, 2-nerved; stamens 3; ovary oblong; style short or absent."

Poa annua f. reptans (Haussknecht) T. Koyama; P. annua var. reptans Haussknecht; P. crassinervis Honda.

Annual Bluegrass is common in most areas of Illinois, although it hasn't been collected from all counties. It is native to Eurasia. Habitats include fields and pastures, lawns and gardens, waste ground, and damp paths in meadows, woodlands, and grassy urban areas. Disturbed areas are strongly preferred. This grass is more abundant during the spring than the fall.

Weed of disturbed, often moist and shady ground; near sea level to 4800 m.

Because Annual Bluegrass dies down during the summer, it supports fewer insect species than other Poa spp. (Bluegrasses). However, some bluegrass feeders that are active during the spring include the caterpillars of Amblyscirtes vialis (Common Roadside Skipper), the caterpillars of Poanes hobomok (Hobomok Skipper), the nymphs of Melanoplus sanguinipes (Migratory Grasshopper), and both adults and nymphs of Eritettix simplex (Velvet-Striped Grasshopper). These insects feed on the foliage. Annual Bluegrass is the preferred host plant of another species, Listronotus maculicollis (Annual Bluegrass Weevil), whose larvae feed on the roots. The seeds of Annual Bluegrass and other Bluegrasses are eaten by the Mourning Dove, English Sparrow, and Field Sparrow. Small mammalian herbivores, like the Cottontail Rabbit and Meadow Vole, eat both the foliage and seedheads.

Plant / epiphyte
fruitbody of Athelia pyriformis grows on living Poa annua

In Great Britain and/or Ireland:
Foodplant / parasite
Blumeria graminis parasitises live Poa annua

Foodplant / parasite
conidial anamorph of Entyloma irregulare parasitises live leaf of Poa annua

Foodplant / gall
stroma of Epichlo causes gall of stem of Poa annua

Foodplant / pathogen
acervulus of Colletotrichum coelomycetous anamorph of Glomerella graminicola infects and damages root of Poa annua

Foodplant / pathogen
Labyrinthula infects and damages Poa annua

Foodplant / pathogen
strand of Laetisaria fuciformis infects and damages dying plant of Poa annua
Remarks: season: 9-10

Foodplant / saprobe
fruitbody of Marasmius curreyi is saprobic on dead, decayed stem of Poa annua

Foodplant / pathogen
Fusarium anamorph of Monographella nivalis infects and damages leaf sheath (usually close to stem base) of Poa annua
Remarks: season: mainly 10-3
Other: major host/prey

Foodplant / feeds on
adult of Oulema melanopus/rufocyanea agg. feeds on leaf of Poa annua
Remarks: season: 1-12

Foodplant / parasite
hypophyllous, long covered by epidermis telium of Puccinia brachypodii var. poae-nemoralis parasitises live leaf of Poa annua

Foodplant / parasite
uredium of Puccinia graminis f.sp. poae parasitises live stem of Poa annua

Foodplant / parasite
sparse uredium of Puccinia poarum parasitises live leaf of Poa annua

Foodplant / spot causer
Spermospora anamorph of Spermospora poagena causes spots on live leaf of Poa annua

Frequent

Fl. & Fr. Per.: throughout most of the year, especially March-September.

The following is a representative barcode sequence, the centroid of all available sequences for this species.

Barcode of Life Data Systems (BOLDS) Stats
Public Records: 25
Specimens with Barcodes: 52
Species With Barcodes: 1

Canada

Rounded National Status Rank: NNA - Not Applicable

United States

Rounded National Status Rank: NNA - Not Applicable

Rounded Global Status Rank: GNR - Not Yet Ranked

The preference is full sun to light shade, moist conditions, and a loam or clay-loam soil. This grass often colonizes damp compacted soil that is devoid of other kinds of vegetation.